A change of one half inch in fin depth can profoundly change the performance of a sailboard or surfboard. Fin boxes now in use (except for the following references ) do not allow the fin to be adjusted vertically. A windsurfer or surfer must remove a larger fin from the fin box and replace it with another smaller fin if he wishes to reduce fin depth.
U.S. Pat. Nos. 5,224,435 and 5,148,761 provide a means to adjust the depth of a fin used in saiboards. Both of these inventions have tried to make the fin adjustable while sailing. This feature may be important to racers, but I do not feel that a complicated adjustment system is necessary for the recreational sailor. While my system is not adjustable while sailing, it does allow the sailor to quickly adjust fin depth in the water. U.S. Pat. No. 5,148,761, and 5,224,435 only allow the user to chose between two radically different fixed fin depth positions, while my fin system will allow the user to adjust the fin depth, angle, and horizontal placement of the fin in very small increments. The inventions shown in U.S. Pat. Nos. 5,224,435, and 5,148,761 are not well suited for surf boards, or sailboards using swept back surf style fins. My fin system will work for any style fin currently being made.